Force-controlled dust extraction polishing end effector and method for fiber composite workpieces

Abstract

The application discloses a force-controlled dust-removing polishing end effector and method for a fiber composite workpiece, and belongs to the technical field of robot polishing. The polishing end effector comprises a base unit, a replaceable tool module, a quick-change disc, a dust conveying channel and a braking mechanism. The base unit is internally provided with a force sensor; the replaceable tool module is integrated with a polishing disc and a dust suction structure; the quick-change disc realizes quick connection and separation of the base unit and the replaceable tool module. The dust conveying channel is internally provided with a flexible isolation section, the rigidity of the flexible isolation section in the length direction thereof is lower than the axial rigidity of the force sensor, so that mechanical vibration and stress transmitted from the replaceable tool module side to the force sensor through the dust conveying channel can be attenuated through flexible deformation of the flexible isolation section. The braking mechanism can automatically brake the polishing disc when a power source is disconnected. The application meets the needs of high-precision constant force control, efficient dust removal, quick tool replacement and safety braking for fiber composite polishing.

Description

Technical Field

[0001] This application relates to the field of robotic polishing technology, and in particular to a force-controlled dust removal polishing end effector and method for fiber composite material workpieces. Background Technology

[0002] Fiber composite materials, such as carbon fiber and glass fiber, have been widely used in high-end equipment fields such as aerospace, wind turbine blades, and rail transportation due to their excellent properties such as high specific strength and fatigue resistance. These workpieces typically have complex curved surface contours, and polishing is a key process to ensure their assembly accuracy and aerodynamic performance. However, in actual production, there are still several technical challenges in the automated polishing of fiber composite materials.

[0003] During the polishing process, fiber composite materials generate a large amount of fine dust. This dust is highly hard, has strong penetrability, and is conductive, making it easy for it to penetrate into the joints of robots, the kinematic pairs of end effectors, and the internal components of pneumatic sensors. This can lead to malfunctions such as jamming, short circuits, and signal drift, shortening the lifespan of the equipment. Furthermore, the dust emission can pollute the working environment and pose a threat to the respiratory health of operators.

[0004] Furthermore, fiber composite workpieces, such as aero-engine blades and wind turbine blade main beams, have high individual value. If the force control is inaccurate during polishing, an over-polishing amount exceeding 0.1 mm may lead to interlayer delamination or fiber exposure, resulting in the scrapping of the workpiece. Therefore, the end effector must have high-precision constant force control capability, and the force sensor detection signal must not be affected by mechanical interference from additional structures such as dust extraction pipes.

[0005] Traditional end effectors typically have rigidly fixed connections for the polishing head, force sensor, and housing. Replacing polishing discs of different sizes or curvatures requires manually tightening and loosening bolts and realigning them, a cumbersome and time-consuming process that impacts the automated operation cycle. Furthermore, the additional piping and connectors added for dust extraction create mechanical coupling with the force sensor, and their vibration and deformation stress directly contaminate the sensor's detection signal, leading to inaccurate constant force control.

[0006] Furthermore, even after the air supply to a traditional pneumatic motor is cut off, the rotor will continue to rotate for several seconds to more than ten seconds due to inertia. In batch operations that require frequent sandpaper changes, the robot has to wait for the polishing disc to stop rotating naturally before it can proceed to the next step, resulting in wasted waiting time.

[0007] In summary, there is currently a lack of an integrated end effector that can simultaneously achieve high-precision force control, efficient dust removal, quick tool change, and safe braking. Summary of the Invention

[0008] This invention provides a force-controlled dust removal and polishing end effector and method for fiber composite material workpieces, to solve the technical problems in the background art, such as high-precision force control, efficient dust removal, quick tool change and safe braking.

[0009] The mutual interference between force control and dust removal stems from the fact that they share a rigid mechanical path. When components such as the dust extraction pipe are connected in series between the force sensor and the working tool, in addition to transporting dust, they also form an additional path for transmitting mechanical vibration and stress to the force sensor.

[0010] The existing design does not distinguish between the force transmission path and the dust conveying path, resulting in the two being physically dependent on each other and mechanically interfering with each other.

[0011] This invention separates the force transmission path from the dust conveying path in the end effector: a flexible isolation section blocks mechanical vibration and stress transmitted from the dust removal system to the force sensor, providing a clean mechanical environment for high-precision force sensing; simultaneously, polishing, dust removal, and other functions are integrated into a replaceable tool module, and quick switching is achieved through a quick-change disc. The technical solution is as follows:

[0012] In a first aspect, the present invention provides a force-controlled dust removal and polishing end effector for fiber composite material workpieces, comprising: a base unit including a force sensor; a replaceable tool module including a polishing disc and a dust collection structure for collecting dust generated during the polishing operation; a quick-change disc for quickly connecting and disconnecting the base unit and the replaceable tool module; a dust conveying channel for discharging dust collected by the dust collection structure; and a braking mechanism configured to automatically brake the polishing disc when the power source driving its operation is disconnected. The dust conveying channel has a flexible isolation section connected in series in the dust conveying path between the force sensor and the quick-change disc; the stiffness of the flexible isolation section along its length is lower than the axial stiffness of the force sensor, so as to attenuate the mechanical vibration and stress transmitted from the replaceable tool module side to the force sensor via the dust conveying channel through its own flexible deformation.

[0013] In this technical solution, the low-rigidity design of the flexible isolation section ensures that the dust conveying path and the force sensor detection path are mechanically independent: most of the polishing contact force is transmitted to the force sensor through the high-rigidity quick-change disc mechanical interface, while the vibration and stress caused by the dust suction pipe are absorbed and isolated by the flexible isolation section, thus ensuring the purity of the force sensor detection signal and providing a physical basis for high-precision constant force control. Simultaneously, the quick-change disc enables rapid replacement of the entire replaceable tool module, the braking mechanism enables automatic braking in case of pressure loss, and the dust suction structure collects dust during the polishing operation.

[0014] Optionally, the flexible isolation section is an axially expandable corrugated pipe or folded pipe. Due to its unique pleated wall structure, the corrugated pipe or folded pipe has natural flexibility in the axial direction, and a very small force can drive it to produce significant expansion and contraction deformation, meeting the requirements for low axial stiffness; at the same time, as a dust conveying pipe, radial shape stability can be ensured by lining it with spiral metal wires.

[0015] Optionally, the axial stiffness of the flexible isolation section is no greater than 50 N / mm; or, the axial stiffness of the flexible isolation section is less than one-tenth of the axial stiffness of the force sensor. Both of these quantitative limitations ensure effective mechanical isolation of the force sensor detection path by the flexible isolation section.

[0016] The base unit may include an upper fixed plate, the force sensor, and a lower fixed plate fixedly connected from top to bottom. The flexible isolation section is connected between the upper fixed plate and the lower fixed plate to form a stable force sensing module.

[0017] The braking mechanism may include a brake cylinder and an L-shaped brake. The L-shaped brake is biased to the braking position by a torsion spring. When the brake cylinder is pressurized, it drives the L-shaped brake to disengage from the polishing disc. When the cylinder is depressurized, it presses the polishing disc against the polishing disc under the action of the torsion spring to achieve braking. This structure achieves a safe design of releasing when pressure is applied and braking when pressure is lost.

[0018] The dust conveying channel may further include a detachable dust guide connection assembly, which includes a first dust guide connector disposed on the base unit and a second dust guide connector disposed on the replaceable tool module. The first dust guide connector is a first rigid tube, and the second dust guide connector is a second rigid tube.

[0019] Optionally, the first rigid tube has an annular groove at its end near the second rigid tube, and the second rigid tube has an annular flange at its end near the first rigid tube that matches the annular groove. This plug-in structure, in conjunction with the dust airflow direction, can achieve a highly reliable seal without an independent sealing ring.

[0020] The dust collection structure may include a dust collection hood that at least partially surrounds the polishing disc, and the dust collection hood has a first dust collection port on the side facing the polishing disc; the working surface of the polishing disc has a second dust collection port; both the first dust collection port and the second dust collection port are connected to the dust conveying channel, forming a dual dust removal system that combines central dust collection and circumferential dust collection.

[0021] In a second aspect, the present invention provides a polishing method using the polishing end effector described in any of the above claims, comprising the following steps:

[0022] Step 1: Install the base unit onto the end of the robot arm;

[0023] Step 2: Connect the replaceable tool module via the quick-change disc;

[0024] Step 3: Start the polishing disc to rotate and start the vacuuming process;

[0025] Step 4: Based on the feedback from the force sensor, constant force polishing control is achieved. When it is necessary to replace the replaceable tool module or sandpaper, the polishing disc is braked by the braking mechanism to perform the replacement.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] First, the flexible isolation section in the dust conveying channel, due to its lower stiffness than the axial stiffness of the force sensor, mechanically separates the dust conveying path from the force transmission path. After the vibration and stress transmitted by the suction pipe are absorbed by the deformation of the flexible isolation section, the force sensor signal primarily reflects the polishing contact force, suppressing pipe interference. Second, the dual suction structure, combining central suction and circumferential encirclement, can simultaneously extract dust generated on the polishing disc's working surface and circumferential dust thrown from the disc's edge, resulting in more comprehensive collection and reducing the intrusion of fine dust into equipment joints and sensors, thus improving the working environment. Third, the quick-change disc allows for rapid connection and separation of the base unit and replaceable tool module. Changing polishing discs of different sizes or curvatures requires no manual pipe connection or alignment, and can be completed within seconds, shortening the auxiliary time for automated polishing operations. Fourth, the braking mechanism employs a pressure-loss triggered braking system, using a torsion spring as an energy storage and reset element. During normal operation, the air source pressure overcomes the torsion spring force, releasing the brake; when the air source pressure is lost, the torsion spring releases its stored energy, and the brake presses against the polishing disc. This design avoids the waiting time caused by inertial rotation after the pneumatic motor stops supplying air, and also has a safety protection function in case of air source failure.

[0028] In addition, the quick-change disc, combined with the detachable dust guide connection assembly, eliminates the need for separate piping operation when changing tools; the flexible isolation section and the arrangement of the force sensor protect the force measurement signal from pipeline interference; and the pressure loss braking and quick-change process allow sandpaper replacement without waiting for the polishing disc to stop rotating.

[0029] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a three-dimensional schematic diagram of a force-controlled dust removal and polishing end effector for fiber composite material workpieces provided in the embodiments of this application;

[0032] Figure 2 This is a three-dimensional schematic diagram of the replaceable tool module and braking mechanism in the force-controlled dust removal and polishing end effector for fiber composite material workpieces provided in the embodiments of this application;

[0033] Figure 3 This is a three-dimensional schematic diagram of the braking mechanism and polishing disc in the force-controlled dust removal and polishing end effector for fiber composite material workpieces provided in the embodiments of this application;

[0034] Figure 4 This is a three-dimensional schematic diagram of the L-shaped brake in the force-controlled dust removal and polishing end effector for fiber composite material workpieces provided in the embodiments of this application;

[0035] Figure 5 yes Figure 1 A three-dimensional schematic diagram of the upper and lower fixing plates and the tool mounting plate;

[0036] Figure 6 yes Figure 1 A schematic diagram showing the separation of the first rigid tube and the second rigid tube.

[0037] Figure 7 yes Figure 1 A three-dimensional structural diagram of the fast disc changer.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1-Base unit; 11-Upper fixing plate; 12-Force sensor; 13-Lower fixing plate; 2-Quick change plate; 21-Robot end; 22-Tool end; 3-Replaceable tool module; 31-Tool mounting plate; 32-Polishing disc; 33-Dust hood; 331-First dust suction port; 4-Dust conveying channel; 41-Flexible isolation section; 42-Separable dust guide connection assembly; 421-First rigid tube; 4211-Annular groove; 422-Second rigid tube; 4221-Annular flange; 5-Braking mechanism; 51-Braking cylinder; 52-L-shaped brake; 521-First arm; 522-Second arm; 53-Torsion spring. Detailed Implementation

[0040] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0041] In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the relative positions of the corresponding components in the direction of gravity when they are in use, while "inner" and "outer" refer to their relative positions to the contours of the corresponding components themselves. Furthermore, the terms "first," "second," etc., used in this application are for distinguishing one element from another and do not imply sequentiality or importance. In the following description, when referring to the accompanying drawings, unless otherwise explained, the same reference numerals in different drawings denote the same or similar elements.

[0042] The present application will now be described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the application.

[0043] First aspect: According to the embodiments of this application, reference is made to Figures 1 to 7 A force-controlled dust removal and polishing end effector for fiber composite workpieces includes a base unit 1, at least one replaceable tool module 3, a quick-change disc 2, and a dust conveying channel 4.

[0044] The base unit 1 houses a force sensor 12 for detecting contact force during the polishing process. The replaceable tool module 3 integrates a polishing disc 32 for performing the polishing operation and a dust collection structure for collecting dust generated during the polishing operation, forming the functional side for task execution and dust collection. The quick-change disc 2 is the hub for achieving quick and reliable connection and separation between the two, while the dust conveying channel 4 is the key path connecting the base unit 1 and the replaceable tool module 3 and for exporting the collected dust.

[0045] The dust conveying channel 4 has a flexible isolation section 41, which is connected in series in the dust conveying path between the force sensor 12 and the quick-change disc 2. The stiffness of the flexible isolation section 41 along its length is lower than the axial stiffness of the force sensor 12, so as to attenuate the mechanical vibration and stress transmitted from the replaceable tool module 3 to the force sensor 12 via the dust conveying channel 4 through its own flexible deformation. This setting can block these mechanical interferences outside the sensing path of the force sensor 12. When the robot performs polishing operations, the polishing disc 32 and the dust collection system on the replaceable tool module 3 side start to work. At this time, two main types of mechanical interference may occur: one is the high-frequency vibration generated by the rotation of the polishing disc 32 itself and its contact with the workpiece; the other is the pipeline stress caused by the airflow pulsation and negative pressure of the dust collection system.

[0046] In traditional designs, the suction pipe is often rigid or has low flexibility. These disturbances can be directly transmitted to the force sensor 12 of the base unit 1 through the suction pipe. Vibrations of the polishing disc 32, airflow pulsations, and even the deformation stress of the pipe itself can all directly contaminate the signal of the force sensor 12 through this path, causing the constant force control based on this signal to become inaccurate.

[0047] This invention introduces a flexible isolation section 41 to physically separate the force transmission path and the dust guiding path, preventing vibrations and stresses during dust transport from being transmitted to the force sensor 12 along a rigid path. The force transmission path is primarily completed via the high-rigidity quick-change disc 2 mechanical interface, ensuring the fidelity of the sensing signal; while dust transport is completed through this flexible isolation section 41. The flexible isolation section 41 absorbs most of the vibrations originating from the working end that are unrelated to the polishing contact force. According to the principle of parallel force transmission, since the stiffness of the flexible isolation section 41 along its length is much lower than the axial stiffness of the force sensor 12, most of the polishing contact force is transmitted through this high-rigidity path and accurately sensed by the force sensor 12, while the interference force transmitted through the dust transport channel 4 is attenuated. This allows high-precision, high-dynamic-response constant force closed-loop control to be stably achieved on the end effector of the integrated dust removal system.

[0048] According to the embodiments of this application, refer to Figure 1 The flexible isolation section 41 can be a corrugated or folded tube that is stretchable along its length. Due to their unique pleated wall structure, corrugated or folded tubes are flexible along their length, allowing them to expand and contract with relatively small forces, thus meeting the low stiffness requirement. During polishing, interference from the replaceable tool module 3 is mostly push-pull or high-frequency micro-amplitude vibration along the length. The expansion and contraction characteristics of the corrugated tube can absorb this energy like a spring and convert it into its own deformation, rather than transmitting it. Simultaneously, as a dust conveying pipe, it must ensure unobstructed flow under internal negative pressure to avoid radial deformation. To this end, a spiral metal wire ring can be lined inside the tube wall during manufacturing. This reinforcement design primarily provides radial support with minimal impact on axial stiffness, thus achieving its integrated design goal of being flexible axially for vibration isolation and robust radially for shape preservation.

[0049] According to an embodiment of this application, the axial stiffness of the flexible isolation section 41 is no greater than 50 N / mm. In practice, the force sensor 12 can be an industrial-grade six-dimensional force sensor, whose stiffness range is typically in the order of 100,000 N / m to 1,000,000 N / m. Therefore, limiting the axial stiffness of the flexible isolation section 41 to no greater than 50 N / mm is determined based on engineering analysis and experimental verification of the stiffness range of industrial-grade six-dimensional force sensors and the magnitude of common interference forces. When the stiffness of the flexible isolation section 41 is constrained below this threshold, according to the mechanical principle of parallel force transmission paths, under the same interference force, the low-stiffness flexible isolation section 41 will bear most of the deformation, while the interference stress shared by the high-stiffness force sensor 12 path is extremely small. For example, using a silicone corrugated pipe with an axial stiffness of approximately 45 N / mm, actual measurements show that the force signal noise, which can reach up to ±15 N when using a rigid pipe in the same position, can be reduced to within ±1 N, with a significant effect.

[0050] According to another embodiment of this application, the determination of the axial stiffness of the flexible isolation section 41 can also be made in another limiting manner, such as the axial stiffness of the flexible isolation section 41 should be less than one-tenth of the axial stiffness of the force sensor 12. Under this limiting method, regardless of whether the force sensor 12 itself is relatively stiff or relatively soft, as long as the dust channel connecting them has a sufficiently low axial stiffness, for example, reaching one-tenth of the stiffness of the force sensor 12, an effective mechanical isolation zone can be established between them. This ensures that the solution of the present invention can be adapted to force sensors 12 of different models and ranges. In effect, when the axial stiffness of the flexible isolation section 41 is less than one-tenth of the axial stiffness of the force sensor 12, the purity of the force sensor 12 signal can meet the requirements of most high-precision constant force polishing processes.

[0051] According to one embodiment of this application, reference is made to... Figure 1 The base unit 1 may include an upper fixed plate 11, a force sensor 12, and a lower fixed plate 13 fixedly connected from top to bottom, with a flexible isolation section 41 connecting the upper fixed plate 11 and the lower fixed plate 13. The upper fixed plate 11 serves as the interface for connecting with the robot arm, providing a stable mounting base; the lower fixed plate 13 serves as the interface for connecting with the quick-change disc 2 and transmits the polishing contact force upwards. The force sensor 12 is clamped between the upper fixed plate 11 and the lower fixed plate 13, ensuring a direct and clear force path and avoiding force flow bypass or stress concentration caused by structural complexity. In addition, this modular design facilitates processing, assembly, and calibration.

[0052] The upper fixing plate 11 and the lower fixing plate 13 can be integrally processed from high-strength aluminum alloy to ensure overall rigidity. The force sensor 12 is fixed in them as a standard part, forming an independent sensing module that can be pre-calibrated.

[0053] The axial stiffness of force sensor 12 refers to its structural stiffness along the installation direction, which is greater than the stiffness of the flexible isolation section 41 along its own length. Force sensor 12 can be a six-dimensional force sensor, which can simultaneously detect in real time the forces (Fx, Fy, Fz) and torques (Mx, My, Mz) generated when the polishing disc 32 contacts the workpiece in three orthogonal directions. In complex polishing operations, especially when processing three-dimensional curved workpieces, the contact state between the polishing disc 32 and the surface is spatially dynamic, and a single axial pressure is insufficient to describe the true contact mechanics. For example, when the polishing disc 32 is in tangential contact with the curved surface, not only is there a normal contact force, but also lateral forces and torques. The six-dimensional force sensor can accurately capture these complex multi-dimensional force signals, providing a complete dataset for the host computer control system. Based on this complete dataset, the control algorithm can not only calculate the compensation required to maintain a constant normal polishing force, but also intelligently identify and compensate for lateral friction and unbalanced torque caused by attitude and path deviations, thereby achieving true three-dimensional constant force control of the polishing contact force and avoiding uneven polishing, over-polishing or under-polishing caused by torque imbalance.

[0054] The quick-change disc 2 used in this invention is a commercially available component with multiple independent gas channels, and is a key component for achieving rapid tool change functionality. The robot end 21 of the quick-change disc 2 is fixed to the lower surface of the lower fixing plate 13, while the tool end 22 is fixed to the upper surface of the tool mounting plate 31. When the replaceable tool module 3 is connected to the base unit 1 via the quick-change disc 2, not only is the mechanical structure locked, but the gas channels between the robot end 21 and the tool end 22 are automatically connected. This makes the entire replaceable tool module 3 an independent functional unit, eliminating the need for any cumbersome manual connection of gas tubes during replacement, thus improving automation and replacement speed.

[0055] According to one embodiment of this application, reference is made to... Figure 2 and Figure 3The braking mechanism 5 is configured in a relatively safe mode: it can automatically brake the polishing disc 32 when the power source driving its operation, such as the air source, is disconnected. Traditional designs often use pressure braking, which requires pressure or electricity to stop the polishing disc 32. This method can lead to braking failure in the event of a power system failure or emergency stop, and the high-speed rotating polishing disc 32 poses a safety hazard. This invention adopts a pressure-loss braking mode, where, during normal operation, the power source, such as compressed air, is continuously supplied to overcome the elastic force of the reset mechanism, such as a spring, within the braking mechanism 5, keeping the brake in the released position and allowing the polishing disc 32 to rotate freely. Once sandpaper needs to be replaced or an abnormal situation occurs, the control system only needs to cut off the power source, and the braking mechanism 5 will automatically and immediately enter the braking state under the drive of the internal reset mechanism, braking the polishing disc 32. This design transforms the sudden air supply interruption into a condition for triggering a safe action, improving the system's safety level. At the same time, from a production efficiency perspective, the braking mechanism allows tool or sandpaper replacement without waiting for the polishing disc 32 to stop naturally.

[0056] According to one embodiment of this application, reference is made to... Figures 2 to 4 The braking mechanism 5 may include a brake cylinder 51 and an L-shaped brake 52. The L-shaped brake 52 is biased towards the braking position by a torsion spring 53. The L-shaped brake 52 is an L-shaped lever, with its first arm 521 in contact with the piston rod of the brake cylinder 51, and its second arm 522 having a friction pad at its end, aligned with the side of the polishing disc 32. The torsion spring 53 always attempts to drive the L-shaped brake 52 to rotate, causing the friction pad to press against the polishing disc 32; this is the default braking state. When pressurized gas is introduced into the brake cylinder 51, the piston rod of the brake cylinder 51 extends, pushing the first arm 521 of the L-shaped brake 52 against the torque of the torsion spring 53, forcing the entire L-shaped brake 52 to rotate, thereby causing the friction pad of the second arm 522 to leave the polishing disc 32, entering the release state. Once the air supply is disconnected, the pressure is lost, the pressure inside the brake cylinder 51 disappears, and the thrust of the piston rod of the brake cylinder 51 immediately disappears. At this moment, the previously compressed torsion spring 53 rapidly releases its stored elastic potential energy, driving the L-shaped brake 52 to rotate in the opposite direction. Under the action of the torsion spring 53, the friction pads move towards the side of the polishing disc 32, achieving rapid braking through friction. The entire process is purely mechanically driven, requiring no sensor feedback or circuit control. The response is direct, rapid, and reliable, realizing the safety logic of braking upon pressure loss.

[0057] According to one embodiment of this application, reference is made to... Figure 5 and Figure 6 In order to achieve rapid connection and sealing of the dust channel during quick change, the dust conveying channel 4 may also include a separable dust guide connection component 42, which is connected to the flexible isolation section 41.

[0058] The detachable dust-guiding connection assembly 42 includes a first dust-guiding connector disposed on the base unit 1 and a second dust-guiding connector disposed on the replaceable tool module 3. For example, the first dust-guiding connector is a first rigid tube 421, and the second dust-guiding connector is a second rigid tube 422. Both the first and second rigid tubes 421 and 422 are made of rigid tubes to ensure the accuracy, durability, and shape stability of the connection, avoiding deformation or damage caused by frequent insertion and removal. The first rigid tube is fixed to the lower fixing plate 13 of the base unit 1, and the second rigid tube is fixed to the tool mounting plate 31. When the quick-change disc 2 completes mechanical locking, the ends of these two rigid tubes are precisely aligned and pressed together. The use of rigid tubes ensures the geometric accuracy of the interface, providing a foundation for subsequent reliable sealing. This design protects the vulnerable flexible parts inside the base unit 1, using robust rigid components only at the interface, thus meeting functional requirements while improving the service life and reliability of the entire system.

[0059] It is understood that the detachable dust guide connection assembly 42 is not limited to this. For example, in another embodiment not shown, the first dust guide connection can also be a perforated rubber pad fixedly connected to the lower surface of the lower fixing plate 13, and the second dust guide connection can be a rigid tube fixedly connected to the upper surface of the tool mounting plate 31. When the quick-change disc 2 drives the replaceable tool module 3 to dock with the base unit 1, the rigid tube abuts against the perforated rubber ring, which can also achieve a sealed connection of the dust conveying channel 4 during docking.

[0060] According to one embodiment of this application, reference is made to... Figure 6 An annular groove 4211 is machined at the end of the first rigid tube 421 near the second rigid tube 422, and a precisely matching annular flange 4221 is machined at the end of the second rigid tube 422 near the first rigid tube 421. When the quick-change disc 2 drive tool module docks with the base unit 1, the annular flange 4221 of the second rigid tube 422 is precisely inserted into the annular groove 4211 of the first rigid tube 421. This design achieves automatic alignment and initial positioning in the radial direction. More importantly, the outer surface of the annular flange 4221 and the inner surface of the annular groove 4211 form a tight circumferential contact surface. The axial clamping force provided when the quick-change disc 2 is finally locked allows the two to form an effective end face seal. Compared to a simple planar clamping seal, this structure has relatively lower requirements for the accuracy of the axial clamping force and can tolerate small alignment errors, resulting in higher sealing reliability. An O-ring can also be placed in the annular groove 4211 for double sealing protection. This structure is moderately difficult to manufacture and has good durability, enabling rapid connection and reliable sealing of dust channels under frequent and quick-change operating conditions.

[0061] It should be further explained that the present invention chooses to set the end of the second rigid tube 422 as an annular flange 4221, while setting the end of the first rigid tube 421 as an annular groove 4211. Because the airflow in the dust conveying channel 4 flows from the second rigid tube 422 to the first rigid tube 421, compared with the case where the airflow direction is opposite, better sealing reliability can be obtained under the same manufacturing precision and clamping force, thereby more effectively preventing dust leakage.

[0062] According to one embodiment of this application, reference is made to... Figure 5 The dust collection structure is a three-dimensional, multi-inlet dust collection system, specifically including a dust collection hood 33 that at least partially surrounds the outside of the polishing disc 32. The dust collection hood 33 has a hollow structure and a first dust collection port 331 is opened on the side facing the polishing disc 32. The interior of the dust collection hood 33 is connected to the dust conveying channel 4. At the same time, a second dust collection port is also provided on the working surface of the polishing disc 32 itself, that is, the lower surface of the polishing disc 32. The dust absorbed by the first dust collection port 331 is discharged through the dust conveying channel, and the dust absorbed by the second dust collection port is output through the gas channel in the quick-change disc 2.

[0063] The dust generated during polishing mainly disperses in two directions: a portion is ground off the workpiece surface under the positive pressure of the polishing disc 32. The second dust suction port located on the working surface of the polishing disc 32 forms a negative pressure zone, which can directly remove this part of the dust from the source. However, a larger and more diffuse portion of dust is thrown out tangentially from the circumferential edge of the polishing disc 32 under the centrifugal force generated by the high-speed rotation of the polishing disc 32. Traditional single-working-surface dust suction is incomplete. The dust suction hood 33 added in this invention forms a semi-enclosed or partially enclosed dust collection chamber around the polishing disc 32. Its lateral first dust suction port 331 generates negative pressure in this chamber, which can suck up and capture the circumferential dust thrown out by centrifugal force, preventing it from spreading throughout the entire working space.

[0064] This dual dust removal mechanism, combining central suction with circumferential trapping, forms a three-dimensional dust collection network. Firstly, it improves the working environment, protects equipment, and prevents secondary dust adhesion from affecting workpiece surface quality. Secondly, all captured dust, regardless of its origin, achieves effective dust removal without introducing additional vibration or stress into the force sensor detection path.

[0065] Secondly, the present invention also proposes a polishing method using any of the above-mentioned polishing end effectors. This polishing method includes the following steps:

[0066] Step 1: Install base unit 1 onto the end effector of the robot arm;

[0067] Step 2: Connect the replaceable tool module 3 via the quick-change disk 2;

[0068] Step 3: Start the polishing disc 32 to rotate and start the vacuuming process;

[0069] Step four: Based on the feedback of force sensor 12, constant force polishing control is realized. When it is necessary to replace the replaceable tool module 3 or sandpaper, the polishing disc 32 is braked by the braking mechanism 5 and then the replacement is performed.

[0070] This polishing method integrates high-performance hardware with automated control software, forming a complete automated closed loop from preparation, operation to maintenance.

[0071] After starting polishing and dust extraction, the system enters a constant force control loop: the robot, carrying the end effector, performs polishing, and force sensor 12 detects the contact force in real time; the host computer compares the detected signal with the ideal constant force value set in the process, and instantly calculates the required pose or force adjustment of the robot end effector through a control algorithm; the robot driver adjusts the movement of the robotic arm in real time accordingly, dynamically stabilizing the polishing force at the set value to ensure the consistency of the processed surface. When it is necessary to replace the replaceable tool module 3 or the sandpaper on it, the air supply is disconnected, and the braking mechanism 5 automatically brakes.

[0072] To make the concept of this invention clearer and easier to understand, a specific embodiment is selected below to describe its complete working process.

[0073] In this embodiment, the base unit 1 includes, from top to bottom, an upper fixing plate 11, a force sensor 12, and a lower fixing plate 13, wherein the force sensor 12 is a six-dimensional force sensor. The flexible isolation section 41 adopts an axial corrugated pipe made of silicone, with a measured axial stiffness of approximately 40 N / mm, and its calculated stiffness is approximately one-twentieth of that of the six-dimensional force sensor. The braking mechanism 5 includes a brake cylinder 51, an L-shaped brake 52, and a torsion spring 53, and is configured for pressure loss braking. The detachable dust guide connection assembly 42 includes a first rigid tube 421 and a second rigid tube 422. The end of the first rigid tube 421 near the second rigid tube 422 is provided with an annular groove 4211, and the end of the second rigid tube 422 near the first rigid tube 421 is provided with an annular flange 4221 that matches the annular groove 4211. The replaceable tool module 3 is also equipped with a circumferential dust suction hood 33, with a first dust suction port 331 on the inner side of the dust suction hood 33 and a second dust suction port on the working surface of the polishing disc 32.

[0074] The working process is as follows: Before operation, the robot installs the base unit 1 on its wrist. Based on the workpiece's surface curvature, the robot retrieves a replaceable tool module 3 equipped with a polishing disc 32 of the corresponding diameter from the tool library and docks it via the quick-change disc 2. At the moment of docking, mechanical locking occurs, the air path is connected, and simultaneously, the annular flange 4221 of the second rigid tube 422 inserts into the annular groove 4211 of the first rigid tube 421, sealing the dust path. Polishing begins; the main air source is opened, one air path drives the polishing motor to rotate, and the other air path enters the brake cylinder 51 and releases the polishing disc 32. The dust collection system is activated. The robot moves along the trajectory, bringing the rotating polishing disc 32 into contact with the workpiece. At this time, the vibration generated by the dust collection system is transmitted to the base unit 1 via the replaceable tool module 3, the second rigid tube 422, and the first rigid tube 421, but is almost entirely absorbed and isolated by the flexible corrugated pipe. The six-dimensional force sensor accurately measures the workpiece contact force and torque. The control system uses this detection signal for real-time closed-loop adjustment to maintain a constant force. Dust is sucked in and discharged through the dust conveying channel. When changing sandpaper, the control system cuts off the brake air circuit, the polishing disc 32 stops rotating, and then the sandpaper can be changed.

[0075] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this application will not describe the various possible combinations separately.

[0076] Furthermore, various different implementations of this application can be combined in any way, as long as they do not violate the spirit of this application, they should also be regarded as the content disclosed in this application.

Claims

1. A force-controlled dust removal and polishing end effector for fiber composite material workpieces, characterized in that, include: The base unit (1) includes a force sensor (12); Replaceable tool module (3), the replaceable tool module (3) includes a polishing disc (32) and a dust collection structure for collecting dust generated during polishing operations; Quick-change disc (2), the quick-change disc (2) is used to realize the quick connection and separation between the base unit (1) and the replaceable tool module (3); Dust conveying channel (4), the dust conveying channel (4) is used to discharge the dust collected by the dust collection structure; as well as Braking mechanism (5), which is configured to automatically brake the polishing disc (32) when the power source driving its action is disconnected; The dust conveying channel (4) has a flexible isolation section (41), which is connected in series in the dust conveying path between the force sensor (12) and the quick-change disc (2). The stiffness of the flexible isolation section (41) along its own length direction is lower than the axial stiffness of the force sensor (12), so as to attenuate the mechanical vibration and stress transmitted from the replaceable tool module (3) to the force sensor (12) via the dust conveying channel (4) through its own flexible deformation.

2. The force-controlled dust removal and polishing end effector for fiber composite material workpieces according to claim 1, characterized in that, The flexible isolation section (41) is an axially expandable corrugated pipe or folded pipe.

3. The force-controlled dust removal and polishing end effector for fiber composite material workpieces according to claim 1 or 2, characterized in that, The axial stiffness of the flexible isolation section (41) is no greater than 50 N / mm.

4. The force-controlled dust removal and polishing end effector for fiber composite material workpieces according to claim 1 or 2, characterized in that, The axial stiffness of the flexible isolation section (41) is less than one-tenth of the axial stiffness of the force sensor (12).

5. The force-controlled dust removal and polishing end effector for fiber composite material workpieces according to claim 1, characterized in that, The base unit (1) includes an upper fixing plate (11), a force sensor (12), and a lower fixing plate (13) fixedly connected from top to bottom, and the flexible isolation section (41) is connected between the upper fixing plate (11) and the lower fixing plate (13).

6. The force-controlled dust removal and polishing end effector for fiber composite material workpieces according to claim 1, characterized in that, The braking mechanism (5) includes a brake cylinder (51) and an L-shaped brake (52). The L-shaped brake (52) is biased to the braking position by a torsion spring (53). When the brake cylinder (51) is pressurized, it drives the L-shaped brake (52) to disengage from the polishing disc (32). When it loses pressure, it presses the polishing disc (32) against the torsion spring (53) to achieve braking.

7. The force-controlled dust removal and polishing end effector for fiber composite material workpieces according to claim 1, characterized in that, The dust conveying channel (4) further includes a detachable dust guide connection assembly (42); the detachable dust guide connection assembly (42) includes a first dust guide connector disposed on the base unit (1) and a second dust guide connector disposed on the replaceable tool module (3), the first dust guide connector being a first rigid tube (421) and the second dust guide connector being a second rigid tube (422).

8. The force-controlled dust removal and polishing end effector for fiber composite material workpieces according to claim 7, characterized in that, The first rigid tube (421) has an annular groove (4211) at the end near the second rigid tube (422), and the second rigid tube (422) has an annular flange (4221) at the end near the first rigid tube (421) that matches the annular groove (4211).

9. The force-controlled dust removal and polishing end effector for fiber composite material workpieces according to claim 1, characterized in that, The dust collection structure includes a dust collection hood (33) that at least partially surrounds the polishing disc (32). The dust collection hood (33) has a first dust collection port (331) on the side facing the polishing disc (32). A second dust collection port is provided on the working surface of the polishing disc (32). Both the first dust collection port (331) and the second dust collection port are connected to the dust conveying channel (4).

10. A polishing method using a force-controlled dust removal polishing end effector for fiber composite workpieces as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Step 1: Install the base unit onto the end of the robot arm; Step 2: Connect the replaceable tool module via the quick-change disc; Step 3: Start the polishing disc to rotate and start the vacuuming process; Step 4: Based on the feedback from the force sensor, constant force polishing control is achieved. When it is necessary to replace the replaceable tool module or sandpaper, the polishing disc is braked by the braking mechanism to perform the replacement.

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